Watercraft such as those known as "personal watercraft" have a hull which defines an engine compartment, and include a water propulsion device. An internal combustion engine is positioned in the engine compartment. An output shaft of the engine is arranged to drive the water propulsion device.
The engine has an intake system which draws air from within the engine compartment and delivers it to the combustion chamber(s) thereof. The watercraft includes one or more air passages leading from a point external to the hull through the hull into the engine compartment.
In addition, the watercraft includes a fuel system for supplying fuel to each combustion chamber of the engine. The fuel system includes a fuel tank positioned in the hull of the watercraft and a fuel pump delivering fuel from the tank to at least one charge former which introduces fuel to the engine.
A throttle control may be provided in the intake system of the engine for controlling the rate of air flow therethrough. In order to accurately control the rate of fuel delivery to the engine, the rate of air flow is measured. This may be accomplished indirectly with a throttle control sensor.
Because the watercraft is operated in the water, water often enters the air passages through the hull. This water may damage sensitive components, such as a throttle position sensor. In addition, water which enters the hull and settles at the lower surface may be thrown about the engine compartment by the spinning output shaft of the engine or by the rocking and pitching movement of the watercraft. This water may also damage sensitive components.
A watercraft arranged to overcome the above-stated problems is desired.